1. Field of the Invention
This invention relates to a transmission mechanism for music box ornament and particularly to a simple and low cost motion transmission mechanism driven by the music box power source for moving the ornament smoothly.
2. Description of the Prior Art
Music box with a moveable ornament is a popular gadget, particularly among young ladies and girls. U.S. Pat. No. 4,987,787 discloses one of the commonly used transmission mechanisms for moving the ornament in a music box. Referring to FIG. 1, it mainly includes a casing A for housing a conventional music box gears therein and supporting an ornament thereon. Within the casing A, there is a drive wheel C with an eccentrical drive stub B which slidably engages with a slot J of a slide link F. The slide link F is supported at two ends by a pair of spaced and vertical guide rods D. Each guide rod D has a coil spring E cushion at the lower portion. The drive wheel C is driven and turned by a conventional wind-up power source of the music box. A tappet rod H has its bottom end attached to the slide link F and its top end engaged with the ornament.
The rotating drive wheel C and the drive stub C move the slide link F up or down reciprocally. The ornament attached to the top of the tappet rod H thus will also be moved reciprocally up or down to create amusement effect while music is sound.
The prior art set forth above has some drawbacks. For instance the coil springs E are for keeping the drive stub C making constant contact with the slide link F in the slot J. The spring force tends to accelerate the wearing of the stub C and the slot J. When the stub C is moved at either end of the slot J, the spring at another end tends to tilt the slide link at another end, thus the up or down movement of the tappet rod H and the ornament is rough and not smoothly. It also tends to accelerate the wearing of the guide rods D and the slide link F and makes the up and down motion of the tappet rod and the ornament even more unstable after long time of use. Moreover the whole structure is rather complicated and bulky. It is difficult to produce and assemble, and costs higher.